Development and Assessment of Detonation-Drivers for Hypervelocity Expansion Tube Ground Testing
Abstract
Approved for Public ReleaseA significant challenge to advancing national hypersonic flight capabilities is recreating the flight env,ironment in ground tests, including test flow characterization. Only a handful of large-scale facilities capable of reproducing flig,ht velocity and altitude exist in the US. Expansion tubes have recovered favorable interest after Paull and Stalker identified acous,tic noise sources that limited the operation of the first facilities from the 1960s. However, a key limitation to facility capabilit,y predictions and to flow quality in expansion tube/tunnel operation is the rupture of the primary diaphragm. Typically 1 to 2 sheet,s of mm-thick metal across the diameter of a large-scale facility, primary diaphragm rupture results in departure from ideal facilit,y operation, shot-to-shot variation of burst pressure, and the generation of particulates - or in the worst-case, fragments - that c,an contaminate the test gas and, propagating at km/s, destroy models.We propose to build on our expertise in high-enthalpy hypersoni,c testing and detonation physics to design, build, test, and characterize detonation drivers for expansion facility operation. The,proposed work proceeds in three stages: i) use of a small-scale toroidal detonation driver (Jackson and Shepherd, 2007) to assess,the operating envelope and resulting flow quality in a shocktube, varying initiation location and driver gas properties, ii) impl,ementation of a detonation driver on an existing 6-in Hypervelocity Expansion Tube (HET) (Dufrene et al., 2007), and iii) investigat,ion of scale-up for a large-diameter, 100ft long expansion tube facility design which leverages modification of an existing 17-in sh,ock tube facility (Liepmann et al., 1962) at Caltech. Diagnostics will include high-speed imaging and shock propagation measurement,s and flow quality assessment using focused laser differential interferometry.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 05, 2022
- Source ID
- N000142212141
Entities
People
- Joseph E. Shepherd
Organizations
- California Institute of Technology
- Office of Naval Research
- United States Navy